I would have liked these bits better if they were the ones I ordered. I ordered a set of smaller bits and got these much bigger bits. Luckily I could use the 25mm but had to order a smaller sized set from Amazon to get the other ones I wanted in time to finish the job. The 25mm bit made a smooth cut in polished porcelain tile. It took too long to get them replaced with what I ordered.
The product is as described, have not had to use them. I have been researching these bits at other retailers and found that this product is as good in quality as much more priced name brands. For the price, I would recommend this product.
No cutting blade was included in this set like the description says, the bits so far are performing well on quartz but haven't tried them on granite countertops yet...
Patrick 
